In high-density cities like San Francisco, Seattle, and Washington, D.C., no group is growing faster than rich college-educated whites without children, according to Census analysis by the economist Jed Kolko. By contrast, families with children older than 6 are in outright decline in these places. In the biggest picture, it turns out that America’s urban rebirth is missing a key element: births.

Cities were once a place for families of all classes. The“basic custom” of the American city, wrote the urbanist Sam Bass Warner, was a“commitment to familialism.” Today’s cities, however, are decidedly not for children, or for families who want children. As the sociologists Richard Lloyd and Terry Nichols Clark put it, they are“entertainment machines” for the young, rich, and mostly childless. And this development has crucial implications—not only for the future of American cities, but also for the future of the U.S. economy and American politics.

More in the full piece, including that even the paragon of urban renewal — NYC — experienced decline this year, principally because there is no room for families.

After 20 years of living in major city centers, I can attest to them feeling more and more difficult for kids and families. Just last week, I reached out to several local churches as I searched for youth groups for our two teens.“Not much going on for youth here in the city,” was the universal response.

Of course, there is more evidence of family-unfriendly cities than my youth ministry anecdote. In the area of construction, for example, the vast majority of new housing that has been installed during the“urban rebirth” is made up of studio, 1-, and 2-bedroom units. My neighborhood was built around 1910, almost entirely with families in mind: three-bedroom units in“two-flat” buildings that were explicitly created for the emerging middle class. Every year there are fewer of these buildings because they are either being replaced with 1-bedroom multi-units for young singles, or they are being converted into urban mansions for the very wealthy.

For sure, cities face many obstacles that are inherent to urban life and population density. But this kind of population decline not one of them; it’s a self-imposed problem resulting from a couple of decades of policy-making and profit-chasing without children and families in mind. If left unchecked, these trends will undo the very urban renaissance that has benefitted the developers and policy makers.